title: Protective effects of epidural analgesia on pulmonary complications after abdominal and thoracic surgery: a meta-analysis.
abstract: OBJECTIVE
  To review the impact of epidural vs systemic analgesia on postoperative pulmonary complications.
  
  
  METHODS
  Search of databases (1966 to March 2006) and bibliographies.
  
  
  METHODS
  Inclusion criteria were randomized comparison of epidural vs systemic analgesia lasting 24 hours or longer postoperatively and reporting of pulmonary complications, lung function, or gas exchange. Fifty-eight trials (5904 patients) were included.
  
  
  METHODS
  Articles were reviewed and data extracted. Data were combined using fixed-effect and random-effects models.
  
  
  RESULTS
  The odds of pneumonia were decreased with epidural analgesia (odds ratio [OR], 0.54; 95% confidence interval [CI], 0.43-0.68), independent of site of surgery or catheter insertion, duration of analgesia, or regimen. The effect was weaker in trials that used patient-controlled analgesia in controls (OR, 0.64; 95% CI, 0.49-0.83) compared with trials that did not (OR, 0.30; 95% CI, 0.18-0.49) and in larger studies (OR, 0.62; 95% CI, 0.47-0.81) compared with smaller studies (OR, 0.37; 95% CI, 0.23-0.58). From 1971-2006, the incidence of pneumonia with epidural analgesia remained about 8% but decreased from 34% to 12% with systemic analgesia (P < .001); consequently, the relative benefit of epidural analgesia decreased also. Epidural analgesia reduced the need for prolonged ventilation or reintubation, improved lung function and blood oxygenation, and increased the risk of hypotension, urinary retention, and pruritus. Technical failures occurred in 7%.
  
  
  CONCLUSIONS
  Epidural analgesia protects against pneumonia following abdominal or thoracic surgery, although this beneficial effect has lessened over the last 35 years because of a decrease in the baseline risk.
authors.affiliation: Klinik für Anästhesiologie und Intensivmedizin, Universitätsklinikum, Albert-Schweitzer-Strasse 33, D-48149 Münster, Germany. poppind@uni-muenster.de
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Pöpping
authors.forename: Nadia
authors.initials: N
authors.lastname: Elia
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Marret
authors.forename: Camille
authors.initials: C
authors.lastname: Remy
authors.forename: Martin R
authors.initials: MR
authors.lastname: Tramèr
mesh_terms: D000005:Abdomen / Q000601:surgery; D015360:Analgesia, Epidural / Q000009:adverse effects / Q000379:methods*; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000009:adverse effects; D019317:Evidence-Based Medicine; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007262:Infusions, Intravenous; D007813:Laparotomy / Q000009:adverse effects / Q000379:methods; D008297:Male; D016017:Odds Ratio; D010149:Postoperative Pain / Q000453:epidemiology / Q000517:prevention & control*; D011014:Pneumonia / Q000453:epidemiology / Q000517:prevention & control*; D011183:Postoperative Complications / Q000517:prevention & control; D011336:Probability; D011659:Pulmonary Gas Exchange; D016032:Randomized Controlled Trials as Topic; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D019616:Thoracic Surgical Procedures / Q000009:adverse effects / Q000379:methods; D016896:Treatment Outcome
chemical_list: D000701:Analgesics, Opioid